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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Birger Lens Mount Reservations

now in Ireland shooting.... headed to London tomorrow to pitch the Burning Man film As The Dust Settles to investors.

Here's a shot from Iceland. Blue Lagoon.
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Ryota Kurata said:
Yes, I am at the end of November.
My order number is 107.242256.
I will use my Contax Zeiss lenses and 17-55 EF-S with Birger mount.

How about this lens with Birger mount?
http://www.usa.canon.com/consumer/controller?act=ModelInfoAct&fcategoryid=151&modelid=17623

I want to use it but expensive as a DSLR lens...

Sorry for my English.
Click to expand...

Features of this new 24mm lens:

Fast f/1.4 aperture
Aspherical and UD lens elements for correction of chromatic aberration
Sub Wavelength structure Coating (SWC) to dramatically reduce ghosting and flare
Circular aperture for pleasing bokeh
USM for full-time manual focus
Lead-free glass (RoHS compliance)
Lens hood and pouch supplied

I would be really curious to see how this modern design lens stacks up against an ultra prime (it's actually faster) or master prime.

We are really starting to see full use of aspherical and UD technology (as well as new coatings) as Canon starts to up the quality of the entire lens line for the new 22+ megapixel cameras.

With coverage for full frame SLR, we would be shooting only the center portion of the lens on the RED and I suspect the quality is VERY high.
 
Thanks guys. Those order dates are helpful.

I guess they haven't gotten too far. I guess something happened again. I thought once they got going, there would be huge batches going out.

Must be the QC.
 
While waiting for the tracking number have been processing on this issue of USM motors.

In the thread of Alesniak's mount Andy said very recently that his experiments show that focus drains a lot of power from the battery. Most likely we all know about conservation of energy, so the immediate question after Andy's comment is, where does all the power end up? The answer is, in heating the motor/coils and in heating the mechanics (such as bearings etc.) of the lens.

In plain words, Andy's comment does seem to talk in the same direction as what Takano-san has been saying.

So, it might be a good idea to be careful in the beginning with the focus, especially so if the camera is used in a warm environment and the extra heat is not transferred away from the lens. Even if there is no sudden damage, still with time overheating may gradually destroy the thin insulation layer of the coil wires. Eventually this may also destroy the coils.
 
got my tracking number.. will be receiving it on the 23rd..

when will the knobs be sent out? or are they sent as full packages now?
 
Do
Lauri Kettunen said:
While waiting for the tracking number have been processing on this issue of USM motors.

In the thread of Alesniak's mount Andy said very recently that his experiments show that focus drains a lot of power from the battery. Most likely we all know about conservation of energy, so the immediate question after Andy's comment is, where does all the power end up? The answer is, in heating the motor/coils and in heating the mechanics (such as bearings etc.) of the lens.

In plain words, Andy's comment does seem to talk in the same direction as what Takano-san has been saying.

So, it might be a good idea to be careful in the beginning with the focus, especially so if the camera is used in a warm environment and the extra heat is not transferred away from the lens. Even if there is no sudden damage, still with time overheating may gradually destroy the thin insulation layer of the coil wires. Eventually this may also destroy the coils.
Click to expand...

Do you think perhaps it's a little bit of a reach to assume the electronic creation of these two mounts is the same?

Also do you believe Erik is lying when he says that in 8 years he's never lost a decent lens to the actions of the mount? I would think if Erik's mounts were destroying lenses, he would not have gotten this far.

A little common sense guessing on my part

I'm curious

Jay
 
Jay A. Kelley said:
Do

Do you think perhaps it's a little bit of a reach to assume the electronic creation of these two mounts is the same?

Also do you believe Erik is lying when he says that in 8 years he's never lost a decent lens to the actions of the mount? I would think if Erik's mounts were destroying lenses, he would not have gotten this far.

A little common sense guessing on my part

I'm curious

Jay
Click to expand...

Jay, just relax, no reason to draw far reaching conclusions. I'm not hinting anything about the Birger mount.

Instead, this whole issue of usm motors has puzzled me and as I happen tp know quite a lot about electromagnetic design have realized that Takano-san indeed seem to have a point. What Andy posted recently seem to point towards the same conclusion: The power taken from the battery, which Andy reported to be quite a lot, cannot disappear into nowhere. Also, Takano-san's argument stems with the fact that the XL-series lenses do not focus as fast as EF-lenses. This is to say, the design principle behind EF-lenses has been to maximize focusing speed.

Erik, as a good engineer, may have already built a system to protect the motors from overloading, for instance, by preventing the users from changing the focus from one position to another too quickly (that is, by limiting the maximum current). I can't know what Erik has designed, but obviously I rely on him because I'm going to install the Birger mount on my camera as soon as the mount arrives.

Whatever is the case, it's not a bad idea to be careful at the first place. If I've got it right, nobody outside Canon has the specs for EF-lenses, and thus the rest of us are just trying to guess or reverse engineering what Canon has done. So outside Canon nobody knows for sure. I've also witnessed colleagues burning usm-motors with their EOS-bodies and thinking backwards those situations could be explained by overloading.

Time will show whether there is a reason for any concern. As it stands now, the issue Takano-san raised should not be labelled a hostile attack. There seems to be a genuine point behind his words.
 
Couple of things:
1: In order to relax, I would have to be stressed... I am not on the list to have a Birger Mount at this time, so I am what you would call a casual observer. I have nothing to stress about.
2: As for "far reaching conclusions" do you mean yours or mine? My conclusions are based on comments from the engineer himself, and the history of the mounts to date and their operational history of the last 8 or so years. So "far reaching" may be a bit of a reach in of itself. The gentleman who warned everyone about the motors may have a point in regard to HIS lab tests, but I feel the direct data and operating history of the product itself to be a better sign of it's actual ability.

As for your points: I cannot say one way or the other. If I felt the need to really understand this situation, I would pick up the phone and speak with Erik. He may not be a Canon engineer, but in this case, he's the next best thing.

Perhaps this is something you should do? It may answer your questions. I am quite sure Erik can be more open with a customer on the phone than he can be on here.

Jay
 
Something that concerns me is that the mounts that have been in the field for the last 8 years have been primarily used for scientific applications, right? And there has been no follow focus for these mounts. Just the computer control of focus and iris. Which I'm sure has worked fine for scientific applications. But there can't be much field experience in terms of the tax put on the lens motors when following focus, as that has not been a feature in any real sense until now.

It just seems, in terms of lenses that aren't working, which I can only guess have never been tested over the last 8 years, heat issues, board issues, etc... that the Red specific mounts are a very different beast than the mounts that have been shipping for a while. So I wonder how much of the existing field data actually relates to this version of the mount.
 
Lauri Kettunen said:
J Also, Takano-san's argument stems with the fact that the XL-series lenses do not focus as fast as EF-lenses. This is to say, the design principle behind EF-lenses has been to maximize focusing speed.
.
Click to expand...

One of the reasons for the difference in speeds of focusing between EF's on EOS and Canon XL's is that their focus detection systems are totally different. Like most video cameras autofocus systems the XL's "hunt" for focus by looking at the video image whereas the EOS series have a set of electronics+optics dedicated to focus giving a much faster and accurate response.

If experience is anything to go by video cameras constantly drive the autofocus motors. The slower speed they do this at is more probably to do with the lower quality autofocus systems not wanting to "overshoot" by too much...

JohnF
 
Jay A. Kelley said:
Perhaps this is something you should do?
Click to expand...

Jay, thanks for your reply. I've always liked to read your posts.

As electromagnetic design is a field I know pretty well I'm just thinking out loudly and posting my thoughts. Guess my point is, after thinking of Takano-san's comments I would not rush and say he does not know what he talks of. But the other way, nothing beyond that. We'll see sooner or later whether there will be issues or not. What ever is the case it will not matter that much for me. I'll adapt with the situation.

Like Parisrem it has also pop up in my mind whether anybody has used EF-lenses with some non-Canon mount and focused constantly the lenses with some external knob (feeding constantly power to the lens).

JohnF, yes, neither do I know precisely why auto focus of XL-series lenses is slower than that of EF-lenses. But, the other way around can easily believe that EF-lenses are optimized to have as fast autofocus as possible. That makes sense. And if so, needless to say, Takano-san's comments make also sense. That is, I have not been able to find so far a single argument that shot down what Takano-san said.
 
Lauri Kettunen said:
JohnF, yes, neither do I know precisely why auto focus of XL-series lenses is slower than that of EF-lenses. But, the other way around can easily believe that EF-lenses are optimized to have as fast autofocus as possible. That makes sense. And if so, needless to say, Takano-san's comments make also sense. That is, I have not been able to find so far a single argument that shot down what Takano-san said.
Click to expand...

A canon Video camera uses the primary sensor, and contrast detection to determine how in focus the image is. It constantly needs to move the lens back and forth moving the image out of focus and back into focus again, to determine if it really has best focus. Lens is continually in motion, and as such the motors are continually energized.

A canon SLR camera uses a secondary sensor to measure how much out of focus the lens is, and then moves it to be in focus. On the less expensive cameras, it does not even do a confirmation of focus, and just takes the picture. On the better cameras it will confirm focus, and reposition if necessary. Servo mode is just an extension of the later. Lens motors are driven when needed.

First one is a problem. Second one isn't... Our usage model is almost exactly like the second, plus a little secret sauce that we threw in, to make up for the differences... people really are making a bigger deal out of this issue than it warrants.

Like I said earlier Takano-san is talking about a problem that we have worked around. Also, when we announce our auto-focus tool, it won't suddenly make the mount do something bad with the lenses...
 
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